Lubricant cooling system



Dec. 13, 1960 E. P. PALMATIER LUBRICANT COOLING SYSTEM Filed Jan. 2,1958 INVENTOR.

EVERETT P. PALMATIER BY ad! Lunnrcarrr CGOLING SYSTEM Everett P.Paimatier, Sovay, N.Y., assignor to Carrier (Iorporation, Syracuse,N.Y., a corporation of Delaware Filed Jan. 2, 1958, Ser. No. 706,630

1 Claim. (Cl. 62468) This invention relates broadly to refrigerationsystems. More particularly this invention pertains to an arrangement forefliciently cooling lubricant used to lubricate the various moving partsof the systems such as a compressor.

As is necessary in any equipment that requires lubrication, cooling ofthe medium utilized as a lubricant is necessary. Heretofore it has beensuggested that the lubricant employed in refrigeration systems having areciprocating or centrifugal compressor as a component thereof, becooled by inserting a heat transfer coil within the sump or crank caseof the compressor. Under those circumstances where the supply oflubricant to the individual elements of the system requiring lubricationis under the influence of either an internally or an externally operatedpump, I have found that the cooling of the lubricant can be effectedefliciently and rapidly by routing a portion of the lubricant supplyline over a portion of the evaporator so that a heat transfer action,resulting in a cooling of the lubricant, will occur.

The chief object of this invention is the provision of an economical andefficient lubrication cooling system for the lubricant used in arefrigeration system to lubricate those parts of the system requiringlubrication.

Another object of the invention involves utilizing a portion of theevaporator that normally contributes little to the overall evaporatorperformance for the purpose of cooling the lubricant in the lubricationsystem.

Other objects and features of the invention will be apparent upon aconsideration of the ensuing specification and drawing wherein thefigure is a diagrammatic representation of a refrigeration system, thelubrication circuit of which is cooled by virtue of a heat transferaction between the lubricant and a portion of the refrigerant in theevaporator.

Referring to the figure compressor normally forwards hot gaseousrefrigerant through the line 11 to condenser 12. Liquefaction of therefrigerant in the condenser occurs by virtue of a heat transfer actionbetween a medium passing over the outer surface of the condenser and therefrigerant within the condenser. Liquified refrigerant flows from thecondenser through expansion valve 13 into evaporator 14 where it isconverted to the vapor phase as air or any other medium flowing over theevaporator gives up its heat to the refrigerant. 'Ihe vaporousrefrigerant then continues through suction line 15 to the compressor 10to complete the circuit.

Lubrication of the moving parts of the compressor is provided by a pump20 having communication with the crankcase of the compressor. Lubricantflowing through the suction line of the pump is discharged through line21 having a portion 22 in heat transfer relation with the return bendsof the evaporator 14. Preferably the evaporator consists of a continuoustubular member comprising a plurality of spaced straight portionsinter-connected at their ends by arcuate tubular members called returnbends. The return bends on a normal evaporator coil of the typedescribed are disposed outside of tube sheets which in effect supportthe continuous tubular member defined by the vertically spaced tubeportions. In other words any extended surface is normally placed on thatportion of the coil in which the parallel runs are located. Thisinvention contemplates utilizing the prime surface of the return bendsto effect a heat transfer action between the refrigerant flowing in thereturn bends and the lubricant flowing in the portion 22 of the line 21.This action serves to prevent sweating of the return bends. The cooledlubricant after it leaves that portion of line 21 in heat transferrelation with the evaporator return bends is forwarded under the actionof the pump to the parts of the compressor requiring lubrication. In theinterest of clarity, the details of the part of the lubrication circuitdisposed within the compressor have been deleted. However, it will beappreciated that the usual and normal reciprocating compressor iscontemplated.

It will thus be apparent that a simple and effective means for coolinglubricant flowing Within the lubrication system of equipment associatedwith a refrigeration machine has been provided, without adding aseparate component to the system and without requiring the piping ofrefrigerant to an oil cooler.

While I have described a preferred embodiment of the invention ti willbe understood that the invention is not limited thereto since it may beotherwise embodied within the scope of the following claim.

I claim:

In a refrigeration system including a compressor, a lubrication systemfor the compressor, a condenser, refrigerant expansion means, and anevaporator comprising tubular means having substantially parallelportions interconnected by end portions to form a path of flow for therefrigerant, means for cooling the lubricant including a line, forming apart of the lubrication supply circuit, having a portion in heattransfer relation with the end portions of the evaporator.

References Cited in the file of this patent UNITED STATES PATENTS Re.24,192 Jarlais Aug. 7, 1956 1,550,856 Whitehead Aug. 26, 1925 2,684,579Hieatt et al July 27, 1954 FOREIGN PATENTS 405,207 Great Britain Feb. 1,1934 426,692 Great Britain Apr. 8, 1935

